1. Field of the Invention
This invention relates to an information recording apparatus, and more particularly to recording interruption control and recording restarting control at the time of interrupting and restarting information recording onto an information storage medium.
2. Description of Related Art
Audio information such as voices and/or music are sometimes recorded, together with corresponding video information, on an information storage medium such as an optical disc after they are compressed. If the recording is temporarily interrupted or stopped during the information recording in response to a temporary recording stop instruction, the extraction of audio information to be recorded is stopped after the reception of the instruction. When the recording restart instruction is received, the extraction of the audio information to be recorded is restarted at the time of the restart instruction to restart the information recording.
According to a conventional control method of the recording interruption and restart which controls extraction state of the audio information to be recorded, if data to be recorded at the time of interruption and restart have large level difference therebetween and the audio information including the interrupted portion is continuously reproduced, a sudden noise may possibly occur at the interruption timing.
In order to overcome this problem, fade-out and fade-in processing are introduced. Namely, at the time of interruption of recording, the audio information to be recorded is faded out after the recording interruption instruction is received. At the time of restarting recording, the audio information to be recorded is faded in after the recording restart instruction is received. Thus, the audio information level at the recording interruption time and the recording restart time are made substantially zero level. Here, “fade-out” is processing which gradually decreases the recording level of audio information finally down to zero level, and “fade-in” is processing which sets the recording level of audio information to zero at first and then gradually increases the recording level up to a normal level.
When audio information is recorded on an information storage medium together with video information corresponding, on time axis basis, to the audio information and the recording is temporarily interrupted and then restarted, it is generally possible to interrupt recording video information immediately after the interruption instruction and to restart the recording video information immediately after the restart instruction. If the video signal recorded before and after the interruption is reproduced, unlike the above mentioned audio information, no noise is introduced to the reproduced video image.
If only the audio information corresponding to the video information is faded out to suppress the noise at the time of interruption, the corresponding video information is not recorded during the fade-out period of the audio information. If the reproduction of the video information and the audio information is restarted after the interruption, the video information is recorded from the position on the storage medium where the video information corresponding to the audio information is interrupted, and audio information is recorded from the position just after the audio information which was faded-out at the time of interruption. As a result, the audio information and the video information are not recorded in correspondence with each other. If the audio information and the video information are reproduced from the position of the interruption to the position of the restart, there is a problem that the audio information and the video information are reproduced in a manner being timely shifted from each other. More specifically, the audio information is reproduced with time lag from the reproduction of the video information. Further, this leads to such a problem that it is impossible to record the audio information and the video information according to common time-information.